1. Technical Field
The present invention relates to a piezoelectric element, a liquid ejecting head, a liquid ejecting apparatus, and a sensor.
2. Related Art
It is desired that a piezoelectric element used for an ink jet type recording head or the like which is known as a typical example of a liquid ejecting head is preferentially oriented to a (100) plane when the crystal system is a rhombohedral crystal in order to substantively enhance the piezoelectric characteristics of a piezoelectric layer. Moreover, for example, in order to preferentially orient lead zirconate titanate (PZT) to the (100) plane, a method of manufacturing a piezoelectric element in which the piezoelectric layer consisting of lead zirconate titanate is formed on a lower part of an electrode through a lead titanate layer, is disclosed (for example, refer to JP-A-2011-238774). In addition, a technique in which a lanthanum nickel oxide (LNO) is used as a seed layer and a bismuth ferrate-based and bismuth titanate-based piezoelectric layer is preferentially oriented to the (100) plane, is disclosed (for example, refer to JP-A-2012-006182). Furthermore, a technique in which a buffer layer configured from a metal element which can form a B site of a PZT crystal is preferentially oriented to the (100) plane as a seed layer, has been proposed (for example, refer to JP-A-2005-340428).
By using such a seed layer, it becomes possible to effectively orient the piezoelectric layer to the (100) plane. However, a problem in which, when the piezoelectric element is driven, the voltage is distributed to the seed layer and the voltage which is applied to the piezoelectric layer drops, and thus a displacement amount of the piezoelectric element is decreased, occurs.
Meanwhile, such a problem exists not only in an ink jet type recording head, similarly, but also, naturally, in other liquid ejecting heads which discharge liquid droplets other than an ink and, in addition, similarly exists in the piezoelectric element or a piezoelectric actuator used instead of the liquid ejecting head.